Exhibit 10.15

COGENT, INC. 2004 Equity INCENTIVE PLAN

NOTICE OF RESTRICTED STOCK BONUS AWARD

Grantees Name:

You (the
Grantee) have been granted shares of Common Stock of the Company (the Award), subject to the terms and conditions of this Notice of Restricted Stock Bonus Award (the Notice), the Cogent, Inc. 2004 Equity Incentive
Plan (the Plan), as amended from time to time, and the Restricted Stock Bonus Award Agreement (the Agreement) attached hereto, as follows. Unless otherwise defined herein, the terms defined in the Plan shall have the same
defined meanings in this Notice.

Date of Award and Vesting Commencement Date

Total Number of Shares

of Common Stock
Awarded

(the Shares)

Vesting
Schedule:

Subject to the Grantees continuous Service and other limitations set forth in this Notice, the Plan and the Agreement,
the Shares will vest in accordance with the following schedule:



| |  |  | 25% of the Shares shall vest twelve months after the Vesting Commencement Date;
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| |  |  | 25% of the Shares shall vest twenty-four months after the Vesting Commencement Date (so that 50% of the Shares shall be vested on such date);
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| |  |  | 25% of the Shares shall vest thirty-six months after the Vesting Commencement Date (so that 75% of the Shares shall be vested on such date); and
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| |  |  | 25% of the Shares shall vest forty-eight months after the Vesting Commencement Date (so that 100% of the Shares shall be vested on such date).
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In the event of the Grantees change in status from Employee, Director or Consultant to any other status of
Employee, Director or Consultant, the Shares shall continue to vest in accordance with the Vesting Schedule set forth above.

For purposes
of this Notice and the Agreement, the term vest shall mean, with respect to any Shares, that such Shares are no longer subject to forfeiture to the Company. Shares that have not vested are deemed Restricted Shares. If the
Grantee would become vested in a fraction of a Restricted Share, such Restricted Share shall not vest until the Grantee becomes vested in the entire Share.

Vesting shall cease upon the date of termination of the Grantees Service for any reason, including death or Disability. In the event the Grantees Service is terminated for any reason, including death or
Disability, any Restricted Shares held by the Grantee immediately following such termination of Service shall be deemed reconveyed to the Company and the Company shall



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thereafter be the legal and beneficial owner of the Restricted Shares and shall have all rights and interest in or related thereto without further action by
the Grantee. Any Additional Securities (as defined in the Agreement) shall be subject to the same restrictions as the Restricted Shares with respect to which such Additional Securities were issued, including without limitation the foregoing
forfeiture provisions.

IN WITNESS WHEREOF, the Company and the Grantee have executed this Notice and agree that the Award is to be
governed by the terms and conditions of this Notice, the Plan and the Agreement.



Cogent, Inc., a Delaware corporationBy:Title:




THE GRANTEE ACKNOWLEDGES AND AGREES
THAT THE SHARES SHALL VEST, IF AT ALL, ONLY DURING THE PERIOD OF THE GRANTEES SERVICE (NOT THROUGH THE ACT OF BEING HIRED, BEING GRANTED THIS AWARD OR ACQUIRING SHARES HEREUNDER). THE GRANTEE FURTHER ACKNOWLEDGES AND AGREES THAT NOTHING IN
THIS NOTICE, THE AGREEMENT NOR THE PLAN SHALL CONFER UPON THE GRANTEE ANY RIGHT WITH RESPECT TO CONTINUATION OF THE GRANTEES SERVICE, NOR SHALL IT INTERFERE IN ANY WAY WITH THE GRANTEES RIGHT OR THE COMPANYS RIGHT TO TERMINATE THE
GRANTEES SERVICE AT ANY TIME, WITH OR WITHOUT CAUSE, AND WITH OR WITHOUT NOTICE. THE GRANTEE ACKNOWLEDGES THAT UNLESS THE GRANTEE HAS A WRITTEN EMPLOYMENT AGREEMENT WITH THE COMPANY TO THE CONTRARY, THE GRANTEES STATUS IS AT WILL.

As a condition to receiving the Shares, the Grantee agrees to refrain from making an election pursuant to Section 83(b) of the Code
with respect to the Shares.

The Grantee acknowledges receipt of a copy of the Plan and the Agreement and represents that he or she is
familiar with the terms and provisions thereof, and hereby accepts the Award subject to all of the terms and provisions hereof and thereof. The Grantee has reviewed this Notice, the Agreement and the Plan in their entirety, has had an opportunity to
obtain the advice of counsel prior to executing this Notice and fully understands all provisions of this Notice, the Agreement and the Plan. The Grantee hereby agrees that all questions of interpretation and administration relating to this Notice,
the Plan and the Agreement shall be resolved by the Committee in accordance with Section 11 of the Agreement. The Grantee further agrees to the venue selection in accordance with Section 12 of the Agreement.



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|Dated: |  |  |  | Signed: |  | 



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COGENT, INC. 2004 EQUITY INCENTIVE PLAN

RESTRICTED STOCK BONUS AWARD AGREEMENT

1. Issuance of Shares.
Cogent, Inc., a Delaware corporation (the Company), hereby issues to the Grantee (the Grantee) named in the Notice of Restricted Stock Bonus Award (the Notice), the Total Number of Shares of Common Stock Awarded
set forth in the Notice (the Shares), subject to the Notice, this Restricted Stock Bonus Award Agreement (the Agreement) and the terms and provisions of the Companys 2004 Equity Incentive Plan (the Plan), as
amended from time to time, which are incorporated herein by reference. Unless otherwise defined herein, the terms defined in the Plan shall have the same defined meanings in this Agreement. All Shares issued hereunder will be deemed issued to the
Grantee as fully paid and nonassessable shares, and the Grantee will have the right to vote the Shares at meetings of the Companys stockholders. The Company shall pay any applicable stock transfer taxes imposed upon the issuance of the Shares
to the Grantee hereunder.

2. Transfer Restrictions. The Shares issued to the Grantee hereunder may not be sold, transferred by
gift, pledged, hypothecated, or otherwise transferred or disposed of by the Grantee prior to the date when the Shares become vested pursuant to the Vesting Schedule set forth in the Notice. Any attempt to transfer Restricted Shares in violation of
this Section 2 will be null and void and will be disregarded.

3. Escrow of Stock. For purposes of facilitating the enforcement
of the provisions of this Agreement, the Grantee agrees that the Restricted Shares shall be delivered, together with an Assignment Separate from Certificate in the form attached hereto as Exhibit A executed in blank by the Grantee, to
the Secretary or Assistant Secretary of the Company, or their designee, to hold in escrow for so long as such Restricted Shares have not vested pursuant to the Vesting Schedule set forth in the Notice, with the authority to take all such actions and
to effectuate all such transfers and/or releases as may be necessary or appropriate to accomplish the objectives of this Agreement in accordance with the terms hereof. The Grantee hereby acknowledges that the appointment of the Secretary or
Assistant Secretary of the Company (or their designee) as the escrow holder hereunder with the stated authorities is a material inducement to the Company to make this Agreement and that such appointment is coupled with an interest and is accordingly
irrevocable. The Grantee agrees that the Restricted Shares may be held electronically in a book entry system maintained by the Companys transfer agent or other third party and that all the terms and conditions of this Section 3 applicable
to certificated Restricted Shares will apply with the same force and effect to such electronic method for holding the Restricted Shares. The Grantee agrees that such escrow holder shall not be liable to any party hereto (or to any other party) for
any actions or omissions unless such escrow holder is grossly negligent relative thereto. The escrow holder may rely upon any letter, notice or other document executed by any signature purported to be genuine and may resign at any time. Upon the
vesting of Restricted Shares, the escrow holder will, without further order or instruction, transmit to the Grantee the certificate evidencing such Shares; provided, however, that no transmittal of certificates evidencing the Shares
will occur unless and until the Grantee has satisfied all Tax Withholding Obligations (as defined in Section 5(c) below).

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4. Additional Securities and Distributions.

(a) Any securities or cash received (other than a regular cash dividend) as the result of ownership of the Restricted Shares (the Additional
Securities), including, but not by way of limitation, warrants, options and securities received as a stock dividend or stock split, or as a result of a recapitalization or reorganization or other similar change in the Companys capital
structure, shall be retained in escrow in the same manner and subject to the same conditions and restrictions as the Restricted Shares with respect to which they were issued, including, without limitation, the Vesting Schedule set forth in the
Notice. The Grantee shall be entitled to direct the Company to exercise any warrant or option received as Additional Securities upon supplying the funds necessary to do so, in which event the securities so purchased shall constitute Additional
Securities, but the Grantee may not direct the Company to sell any such warrant or option. If Additional Securities consist of a convertible security, the Grantee may exercise any conversion right, and any securities so acquired shall constitute
Additional Securities. In the event of any change in certificates evidencing the Shares or the Additional Securities by reason of any recapitalization, reorganization or other transaction that results in the creation of Additional Securities, the
escrow holder is authorized to deliver to the issuer the certificates evidencing the Shares or the Additional Securities in exchange for the certificates of the replacement securities.

(b) The Company shall disburse to the Grantee all regular cash dividends with respect to the Shares and Additional Securities (whether vested or not),
less any applicable withholding obligations.

5. Taxes.

(a) No Section 83(b) Election. As a condition to receiving the Shares, the Grantee agrees to refrain from making an election pursuant to
Section 83(b) of the Code with respect to the Shares.

(b) Tax Liability. The Grantee is ultimately liable and responsible for
all taxes owed by the Grantee in connection with the Award, regardless of any action the Company or any Affiliate takes with respect to any tax withholding obligations that arise in connection with the Award. Neither the Company nor any Affiliate
makes any representation or undertaking regarding the treatment of any tax withholding in connection with the grant or vesting of the Award or the subsequent sale of Shares subject to the Award. The Company and its Affiliates do not commit and are
under no obligation to structure the Award to reduce or eliminate the Grantees tax liability.

(c) Payment of Withholding
Taxes. Prior to any event in connection with the Award (e.g., vesting) that the Company determines may result in any tax withholding obligation, whether United States federal, state, local or non-U.S., including any employment tax obligation
(the Tax Withholding Obligation), the Grantee must arrange for the satisfaction of the minimum amount of such Tax Withholding Obligation in a manner acceptable to the Company. The Grantees acceptance of this Award constitutes the
Grantees instruction and authorization to the Company and any brokerage firm determined acceptable to the Company for such purpose to sell on the Grantees behalf a whole number of Shares from those Shares issuable to the Grantee as the
Company determines to be appropriate to generate cash proceeds sufficient to satisfy the minimum applicable Tax Withholding Obligation. Such Shares will be sold on the day such Tax Withholding Obligation arises (e.g., a vesting date) or as soon
thereafter as practicable. The Grantee will be responsible for all brokers fees and other costs of sale, and the Grantee agrees to indemnify and hold the Company harmless from any losses, costs, damages, or expenses relating to any such sale.
To the extent the proceeds of such sale exceed the Grantees minimum Tax Withholding Obligation, the Company agrees to pay such excess in cash to the Grantee. The Grantee acknowledges that the Company or its designee is under no obligation to
arrange for such sale at any particular price, and that the proceeds of any such sale may not be sufficient to satisfy the Grantees minimum Tax Withholding Obligation. Accordingly, the Grantee agrees to pay to the Company or any Affiliate as
soon as practicable, including through additional payroll withholding, any amount of the Tax

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Withholding Obligation that is not satisfied by the sale of Shares described above.

Notwithstanding the foregoing, the Company also may satisfy any Tax Withholding Obligation by offsetting any amounts (including, but not limited to, salary, bonus and severance payments) due to the Grantee by the
Company.

6. Stop-Transfer Notices. In order to ensure compliance with the restrictions on transfer set forth in this Agreement, the
Notice or the Plan, the Company may issue appropriate stop transfer instructions to its transfer agent, if any, and, if the Company transfers its own securities, it may make appropriate notations to the same effect in its own records.
The Company may issue a stop transfer instruction if the Grantee fails to satisfy any Tax Withholding Obligations.

7.
Refusal to Transfer. The Company shall not be required (i) to transfer on its books any Shares that have been sold or otherwise transferred in violation of any of the provisions of this Agreement or (ii) to treat as owner of such
Shares or to accord the right to vote or pay dividends to any purchaser or other transferee to whom such Shares shall have been so transferred.

8. Restrictive Legends. The Grantee understands and agrees that the Company shall cause the legends set forth below or legends substantially equivalent thereto, to be placed upon any certificate(s) evidencing ownership of the Shares
together with any other legends that may be required by the Company or by state or federal securities laws:

THE SHARES
REPRESENTED BY THIS CERTIFICATE ARE RESTRICTED BY THE TERMS OF THAT CERTAIN RESTRICTED STOCK BONUS AWARD AGREEMENT BETWEEN THE COMPANY AND THE NAMED STOCKHOLDER. THE SHARES REPRESENTED BY THIS CERTIFICATE MAY BE TRANSFERRED ONLY IN ACCORDANCE WITH
SUCH AGREEMENT, A COPY OF WHICH IS ON FILE WITH THE SECRETARY OF THE COMPANY.

9. Entire Agreement: Governing Law. The Notice, the
Plan and this Agreement constitute the entire agreement of the parties with respect to the subject matter hereof and supersede in their entirety all prior undertakings and agreements of the Company and the Grantee

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with respect to the subject matter hereof, and may not be modified adversely to the Grantees interest except by means of a writing signed by the
Company and the Grantee. These agreements are to be construed in accordance with and governed by the internal laws of the State of California without giving effect to any choice of law rule that would cause the application of the laws of any
jurisdiction other than the internal laws of the State of California to the rights and duties of the parties. Should any provision of the Notice or this Agreement be determined to be illegal or unenforceable, the other provisions shall nevertheless
remain effective and shall remain enforceable.

10. Construction. The captions used in the Notice and this Agreement are inserted
for convenience and shall not be deemed a part of the Award for construction or interpretation. Except when otherwise indicated by the context, the singular shall include the plural and the plural shall include the singular. Use of the term
or is not intended to be exclusive, unless the context clearly requires otherwise.

11. Administration and
Interpretation. Any question or dispute regarding the administration or interpretation of the Notice, the Plan or this Agreement shall be submitted by the Grantee or by the Company to the Committee. The resolution of such question or dispute by
the Committee shall be final and binding on all persons.

12. Venue. The parties agree that any suit, action, or proceeding arising
out of or relating to the Notice, the Plan or this Agreement shall be brought in the United States District Court for the Central District of California (or should such court lack jurisdiction to hear such action, suit or proceeding, in a California
state court in the County of Los Angeles) and that the parties shall submit to the jurisdiction of such court. The parties irrevocably waive, to the fullest extent permitted by law, any objection the party may have to the laying of venue for any
such suit, action or proceeding brought in such court. If any one or more provisions of this Section 12 shall for any reason be held invalid or unenforceable, it is the specific intent of the parties that such provisions shall be modified to
the minimum extent necessary to make it or its application valid and enforceable.

13. Notices. Any notice required or permitted
hereunder shall be given in writing and shall be deemed effectively given upon personal delivery, upon deposit for delivery by an internationally recognized express mail courier service or upon deposit in the United States mail by certified mail (if
the parties are within the United States), with postage and fees prepaid, addressed to the other party at its address as shown in these instruments, or to such other address as such party may designate in writing from time to time to the other
party.

END OF AGREEMENT

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EXHIBIT A

STOCK ASSIGNMENT SEPARATE FROM CERTIFICATE

FOR VALUE RECEIVED,
 hereby sells, assigns and transfers unto
,
 () shares of the Common Stock of
Cogent, Inc., a Delaware corporation (the Company), standing in his name on the books of, the Company, and does hereby irrevocably constitute and appoint the Secretary of the Company attorney to transfer the said stock in the books of
the Company with full power of substitution.



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|DATED: |  |  |  |  |  |  |  | 
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[Please sign this document but do not date it. The date and information of the transferee will be completed if
and when the shares are assigned.]